PRFAR
PRFAR,
Lab
, Option
,
VAR1B
, VAR1E
,
NVAR1
, VAR2B
,
VAR2E
, NVAR2
,
VAL1
, VAL2
,
VAL3
, VAL4
,
VAL5
, LDSTEP
,
SUBSTEP
, FREQB
,
FREQE
, PrintType
,
LogOpt
Prints acoustic far field parameters.
Lab
Parameters to print:
PRES
—
Acoustic parameters
PROT
—
Acoustic parameters with the y-axis rotated extrusion (not valid for 2D elements)
PLAT
—
Acoustic parameters radiated by a vibrating structural panel (not valid for 2D elements)
Option
Print option, based on the specified print parameter type:
Lab
Option
PRES, PROT, or PLAT SUMC -- Maximum pressure (default)
PHSC -- Pressure phase angle
SPLC -- Sound pressure level
SPAC – A-weighted sound pressure level (dBA)
DGCT -- Acoustic directivity
PSCT -- Maximum scattered pressure
TSCT -- Target strength
PWL -- Sound power level
The arguments VAR1B
,
VAR1E
, NVAR1
,
VAR2B
, VAR2E
,
NVAR2
, and VAL1
are used when
Option
= SUMC, PHSC, SPLC, SPAC, DGCT, PSCT, or TSCT:
VAR1B
,VAR1E
Starting and ending values for the first variable associated with
PrintType
as described below.When
PrintType
= blank (default) or SPHR: Starting and ending phi (φ) angles (in degrees) in the spherical coordinate system. Defaults to 0.When
PrintType
= PLXY: Starting and ending x value in the Cartesian coordinate system. Defaults to 0.When
PrintType
= PLYZ: Starting and ending y value in the Cartesian coordinate system. Defaults to 0.When
PrintType
= PLXZ: Starting and ending x value in the Cartesian coordinate system. Defaults to 0.NVAR1
Number of divisions between the starting and ending
VAR1
values for data computations. Defaults to 0.VAR2B
,VAR2E
Starting and ending values for the second variable associated with
PrintType
as described below.When
PrintType
= blank (default) or SPHR: Starting and ending theta (θ) angles (in degrees) in the spherical coordinate system. Defaults to 0 for a 3D model and 90 for a 2D extrusion model.When
PrintType
= PLXY: Starting and ending y value in the Cartesian coordinate system. Defaults to 0.When
PrintType
= PLYZ: Starting and ending z value in the Cartesian coordinate system. Defaults to 0.When
PrintType
= PLXZ: Starting and ending z value in the Cartesian coordinate system. Defaults to 0.NVAR2
Number of divisions between the starting and ending
VAR2
values for data computations. Defaults to 0.VAL1
VAL1
is additional input. Its meaning depends on thePrintType
argument as described below.When
PrintType
= blank (default) or SPHR: Radius of the sphere surface.When
PrintType
= PLXY: Fixed z value for an X-Y plane in the Cartesian coordinate system. Defaults to 0.When
PrintType
= PLYZ: Fixed x value for a Y-Z plane in the Cartesian coordinate system. Defaults to 0.When
PrintType
= PLXZ: Fixed y value for an X-Z plane in the Cartesian coordinate system, Defaults to 0.
The arguments VAL2
through
VAL5
are additional input used with certain
Lab
and Option
settings as described
below.
VAL2
When
Option
= SPLC or SPAC: Reference rms sound pressure. Defaults to 2x10-5 Pa.When
Option
= PWL: Reference sound power. Defaults to 1x10-12 watts.VAL3
When
Lab
= PRES: Thickness of 2D model extrusion in the z direction (no default).When
Lab
= PROT: Angle of the y-axis rotated extrusion model (no default)VAL4
When
Lab
= PLAT: Mass density of acoustic fluid.VAL5
When
Lab
= PLAT: Sound speed in acoustic fluid.LDSTEP
Specified load step. Defaults to the load step number specified on the SET command, or defaults to 1 if SET has not been issued.
n
—
Load step number.
ALL
—
All load steps.
SUBSTEP
Specified substep. Defaults to the substep number specified on the SET command, or defaults to ALL (all substeps at the specified load step) if SET has not been issued.
n
—
Substep number.
ALL
—
All substeps.
FREQB
Frequency value representing one of the following:
Beginning frequency of the frequency range (
FREQB
toFREQE
) for the defined load step(s) and substeps (SUBSTEP
= ALL). If aSUBSTEP
value is specified,FREQB
is invalid.Central frequency of octave bands, used when
LogOpt
= OB1, OB2, OB3, OB6, OB12, or OB24 andFREQE
is blank.
FREQE
Ending frequency of the frequency range (
FREQB
toFREQE
) for the defined load step(s) and substeps (SUBSTEP
= ALL). If blank,FREQE
is set toFREQB
. If aSUBSTEP
value is specified,FREQE
is invalid.PrintType
Print out far-field parameters on a plane or sphere (used when
Option
= SUMC, PHSC, SPLC, SPAC, DGCT, PSCT, or TSCT). No default.PLXY
—
On an X-Y plane.
PLYZ
—
On a Y-Z plane.
PLXZ
—
On an X-Z plane.
SPHR
—
On a sphere surface.
LogOpt
Octave bands (used only when Option = SPLC, SPAC, or PWL):
OB0
—
Narrow bands (default).
OB1
—
Octave bands.
OB2
—
1/2 octave bands.
OB3
—
1/3 octave bands.
OB6
—
1/6 octave bands.
OB12
—
1/12 octave bands.
OB24
—
1/24 octave bands.
Notes
The PRFAR command prints pressure far fields and far field parameters as determined by the equivalent source principle. Use this command to print pressure and acoustic parameters. See the HFSYM command for the model symmetry and the HFANG command for spatial radiation angles.
Printing acoustic parameters radiated by a vibrating structural panel
(Lab
= PLAT) is supported by elements
SOLID185, SOLID186,
SOLID187, SHELL181,
SHELL281, and SOLSH190. The vibration surface
of the panel must be flagged by the SF,MXWF command.